<template>
    <div class="upload-file">
        <el-upload
                multiple
                :action="uploadFileUrl"
                :before-upload="handleBeforeUpload"
                :file-list="fileList"
                :limit="limit"
                :on-error="handleUploadError"
                :on-exceed="handleExceed"
                :on-success="handleUploadSuccess"
                :show-file-list="false"
                :headers="headers"
                class="upload-file-uploader"
                ref="fileUpload"
        >
            <!-- 上传按钮 -->
            <el-button type="primary">选取文件</el-button>
        </el-upload>
        <!-- 上传提示 -->
        <div class="el-upload__tip" v-if="showTip">
            请上传
            <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
            <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b></template>
            的文件
        </div>
        <!-- 文件列表 -->
        <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear"
                          tag="ul">
            <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content"
                v-for="(file, index) in fileList">
                <el-link :href="`${baseUrl}${file.url}`" :underline="false" target="_blank">
                    <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
                </el-link>
                <div class="ele-upload-list__item-content-action">
                    <el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
                </div>
            </li>
        </transition-group>
    </div>
</template>

<script setup>
    import {getToken} from "@/utils/auth";

    const props = defineProps({
        modelValue: [String, Object, Array],
        // 数量限制
        limit: {
            type: Number,
            default: 5,
        },
        // 大小限制(MB)
        fileSize: {
            type: Number,
            default: 5,
        },
        // 文件类型, 例如['png', 'jpg', 'jpeg']
        fileType: {
            type: Array,
            default: () => ["doc", "xls", "ppt", "txt", "pdf"],
        },
        // 是否显示提示
        isShowTip: {
            type: Boolean,
            default: true
        }
    });

    const {proxy} = getCurrentInstance();
    const emit = defineEmits();
    const number = ref(0);
    const uploadList = ref([]);
    const baseUrl = import.meta.env.VITE_APP_BASE_API;
    const uploadFileUrl = ref(import.meta.env.VITE_APP_BASE_API + "/common/upload"); // 上传文件服务器地址
    const headers = ref({Authorization: "Bearer " + getToken()});
    const fileList = ref([]);
    const showTip = computed(
        () => props.isShowTip && (props.fileType || props.fileSize)
    );

    watch(() => props.modelValue, val => {
        if (val) {
            let temp = 1;
            // 首先将值转为数组
            const list = Array.isArray(val) ? val : props.modelValue.split(',');
            // 然后将数组转为对象数组
            fileList.value = list.map(item => {
                if (typeof item === "string") {
                    item = {name: item, url: item};
                }
                item.uid = item.uid || new Date().getTime() + temp++;
                return item;
            });
        } else {
            fileList.value = [];
            return [];
        }
    }, {deep: true, immediate: true});

    // 上传前校检格式和大小
    function handleBeforeUpload(file) {
        // 校检文件类型
        if (props.fileType.length) {
            const fileName = file.name.split('.');
            const fileExt = fileName[fileName.length - 1];
            const isTypeOk = props.fileType.indexOf(fileExt) >= 0;
            if (!isTypeOk) {
                proxy.$modal.msgError(`文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`);
                return false;
            }
        }
        // 校检文件大小
        if (props.fileSize) {
            const isLt = file.size / 1024 / 1024 < props.fileSize;
            if (!isLt) {
                proxy.$modal.msgError(`上传文件大小不能超过 ${props.fileSize} MB!`);
                return false;
            }
        }
        proxy.$modal.loading("正在上传文件，请稍候...");
        number.value++;
        return true;
    }

    // 文件个数超出
    function handleExceed() {
        proxy.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
    }

    // 上传失败
    function handleUploadError(err) {
        proxy.$modal.msgError("上传文件失败");
    }

    // 上传成功回调
    function handleUploadSuccess(res, file) {
        if (res.code === 200) {
            uploadList.value.push({name: res.fileName, url: res.fileName});
            uploadedSuccessfully();
        } else {
            number.value--;
            proxy.$modal.closeLoading();
            proxy.$modal.msgError(res.msg);
            proxy.$refs.fileUpload.handleRemove(file);
            uploadedSuccessfully();
        }
    }

    // 删除文件
    function handleDelete(index) {
        fileList.value.splice(index, 1);
        emit("update:modelValue", listToString(fileList.value));
    }

    // 上传结束处理
    function uploadedSuccessfully() {
        if (number.value > 0 && uploadList.value.length === number.value) {
            fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
            uploadList.value = [];
            number.value = 0;
            emit("update:modelValue", listToString(fileList.value));
            proxy.$modal.closeLoading();
        }
    }

    // 获取文件名称
    function getFileName(name) {
        // 如果是url那么取最后的名字 如果不是直接返回
        if (name.lastIndexOf("/") > -1) {
            return name.slice(name.lastIndexOf("/") + 1);
        } else {
            return name;
        }
    }

    // 对象转成指定字符串分隔
    function listToString(list, separator) {
        let strs = "";
        separator = separator || ",";
        for (let i in list) {
            if (list[i].url) {
                strs += list[i].url + separator;
            }
        }
        return strs != '' ? strs.substr(0, strs.length - 1) : '';
    }
</script>

<style scoped lang="scss">
    .upload-file-uploader {
        margin-bottom: 5px;
    }

    .upload-file-list .el-upload-list__item {
        border: 1px solid #e4e7ed;
        line-height: 2;
        margin-bottom: 10px;
        position: relative;
    }

    .upload-file-list .ele-upload-list__item-content {
        display: flex;
        justify-content: space-between;
        align-items: center;
        color: inherit;
    }

    .ele-upload-list__item-content-action .el-link {
        margin-right: 10px;
    }
</style>
